$(".sec-banner1-btn i").mouseover(function () {
   $(this).parents(".sec-banner1-btn").siblings("#lunbo").children(".tab").find(".aa").
   eq($(this).index()).css({"opacity":"1","transition":"1s"})
       .siblings(".aa").css({"opacity":"0","transition":"1s"})
   $(this).css({"background-color":"#eb8c27"}).siblings().css({"background-color":"black"})
})